-3db limits for dummies


can someone explain what these numbers mean to the lay person trying to set up an HT system. upper and lower -3db response...

I am tyring to set my 3 channel HT system to sound better and I don't really understand the best way to optimize crossover freq.

Bottom line I moved and some of my equipment is out of order, so for time being I'm stuck with Onkyo txsr705 receiver as amp, in room that is very reflective and it sounds wierd. sounds like tin... I'm sure my other AMP and my old big center provided a lot of depth and better sound...but for now this is where I'm at...
Hardwood floors. Polk RTI 10 right and left. new in wall center Polk 265 Timbre matched . spikes on speakers *should I take them off on hardwood?

Center Speaker info
Efficiency
91 dB
Recommended Amplifier Power
10-200 watts per channel
Total Frequency Response
30Hz-27kHz
Upper -3dB Limit
25 kHz
Lower -3dB Limit
45 Hz
Nominal Impedance
8 ohms

RTI10s
Total Frequency Response
20Hz-27kHz
Upper -3dB Limit
26kHz
Lower -3dB Limit
35Hz
Nominal Impedance
8 ohm
Efficiency
89 dB
Crossover
Subwoofer Crossover
125Hz, 12dB/octave low pass
Mid-High Array Crossover
2.7kHz, 12dB/octave low and high pass. 125Hz 12dB/octave high pass
Recommended Amplifier Power
20-300 watts per channel

I also have a sub PSW 505 I have not hooked up because my preouts on my receiver are blown...
any suggestions on how my system should be set on receiver before PSW to optimize sound and after I hook it up.

Total Frequency Response
23Hz - 160Hz
Upper -3dB Limit
125Hz
Lower -3dB Limit
28Hz
riasillo

Showing 1 response by realremo

I don't know the exact scientific answer, Almarg can maybe speak to this, but I think that the +/-3dB is a range within which a speaker's frequency response is tested. I have also seen a +/-6dB range, on the specs for the Quad 22L2, and have read that this wide a range means that the extreme points of the frequency response can actually vary widely. keeping the specification within +/-3dB results in a more dependable rating of the low and high frequency responses.
I think.